A sentinel node is the first lymph node a cancer has traveled to if it has spread.

After Morton presented findings on his work with melanoma in 1990, his technique was rapidly adopted and, by 1995, the technique was being practiced all over the world.

Dr. Armando E. Giuliano, Joyce Eisenberg Keefer Breast Center director, further developed the technique for breast cancer and introduced his findings in 1993.

Within four years, the sentinel node technique became the standard treatment at major cancer centers.

Morton says the sentinel node technique has changed the way cancer is staged and treated, “saving millions of patients with breast cancer and melanoma from undergoing radical surgery that they didn’t need.”

It was known that 90 percent of human cancers that spread did so through the lymphatic system. What was not known was how to find out if the cancer had actually spread to the lymph nodes without performing radical lymph node surgery — which involved removing 25 or more lymph nodes.

Removing so many lymph nodes left patients with extended hospital stays and chronic complications such as swelling, pain, numbness and limited range of motion.

Morton discovered in his work on melanoma that 99 percent of the time, if the tumor cells had spread to the lymph nodes, then tumor cells would also be present in the sentinel node.

Morton then questioned the practice of removing 25 or more lymph nodes when the spread of cancer could be determined by removing the sentinel node and one or two more.

From his findings, he introduced the sentinel node technique.

Morton also believed, and confirmed, that if this discovery proved true for melanoma, it should also be true for any cancer that spreads through lymphatics, such as breast, colon and lung cancer.

Since this initial breakthrough, Morton has worked in conjunction with pathologists and molecular oncologists at John Wayne Cancer Institute to develop more sensitive ways of finding cancer cells within the sentinel node, such as by the use of molecular markers to detect tumor cells too small for the eye to see.

These advancements enable doctors to examine the lymph nodes in more detail and find metastases (where the cancer has spread) they might not have found before, according to Giuliano.

“The treatment of breast cancer has become less radical and more concerned with the quality of life of a patient, as well as prolonging life,” Giuliano says.

With these advancements, and now that the sentinel node technique is used to treat melanoma, breast and colon cancer, the International Sentinel Node Society hopes that by uniting world leaders in the technique, the society can further research and create standards of care guidelines for the sentinel node technique.

“The sentinel node concept is simple but the learning curve is hard,” Morton says. He adds that a surgeon needs to perform a minimum of 15, and optimally 30, surgeries before being experienced in the technique.

He also says that, while the concept is universal, the application varies between countries.

Morton, the first president of the International Sentinel Node Society, says the exchange of information between groups will enable researchers to continue to develop better techniques that will make it easier for doctors to perform the procedure so that cancer patients everywhere can benefit.

He adds that some new techniques will be presented at the conference.

“We’re interested in the technique being more widely applied throughout the rest of the world,” Giuliano says.

He says it takes time, noting that it took years for the lumpectomy (the surgical removal of a breast cyst or tumor) to be widely used.

“We also want to understand more about the biology of breast cancer and how it spreads and how we can cure it,” he adds.

The conference will also discuss the risks and benefits of sentinel node biopsy in cancer patients at high risk for metastases and the current status and future of sentinel node surgery, and special sessions will discuss the status of major sentinel node clinical trials and molecular approaches to cancer care.

“It’s amazing to think we changed the way a disease is treated from right here in Santa Monica,” Giuliano says.